Patent GB-804670-A (GB)
Title: New optical sensitisers
Inventor: MAGSON MAURICE SUGDEN
IPC: C09B23/10
Filed: 1956-01-09
Abstract: Compounds of the general formula <FORM:0804670/IV (b)/1> wherein m is O or 1, X is bromide or iodide, Y is a polymethylene or xylylene radical and B completes a 5- or 6-membered heterocyclic nucleus, are prepared (i) when n is O and D is -S- alkyl, by reacting a heterocyclic nitrogen compound having an a - or g - -S- alkyl group with a dibromide YBr2 or di-iodide YI2, and (ii) when n is 1 or 2 and D is arylamino or acetarylamino, by reacting a heterocyclic nitrogen compound having an a - or g -methyl group with a dibromide YBr2 or di-iodide Y12, and condensing the product with N:N1-diphenylformamidine or g -anilinoacraldehyde anil, either alone or in the presence of acetic anhydride.  The heterocyclic compound in (i) may be 2-methyl thiobenzthiazole, 2-ethylthiobenzoxazole, or 2-methylthio-a -napththathiazole, and that in (ii) may be 2-methylbenzimidazole, a - or g -picoline, quinaldine, lepidine, 2:5-dimethyl1:3:4 - thiadiazole, 2 - methylthiazoline, 2-methyl - 5 - chlorobenzthiazole, 2 - methylbenzoxazole, 2 - methyl - 5 - phenylbenzoxazole, 2:3 - dimethylbenzimidazole or 2 - methyl - b -naphthathiazole.  The bromide or iodide may be p-xylylene dibromide, ethylene di-iodide, tetramethylene dibromide, pentamethylene dibromide or decamethylene dibromide.  Detailed preparations describe (1) the reaction of 2:5-dimethyl - 1:3:4 - thiadiazole with pentamethylene dibromide to give 3:31 - pentamethylene bis - (2:5 - dimethyl - 1:3:4 - thiadiazolium bromide), which is then reacted with N:N1-diphenylformamidine in acetic anhydride to give 3:31 - pentamethylene bis - (2 - b  - acetanilidovinyl - 5 - methyl - 1:3:5 - thiodiazolium bromide); (2) the reaction of 2-methylthiazoline with tetramethylene dibromide to give 3:31-tetramethylene bis - (2 - methyl - 4:5 - dihydrothiazolium bromide), which is then reacted with N:N1-diphenylformamidine in acetic anhydride to give 3:31 - tetramethylene bis - (2 - b -acetanilidovinyl - 4:5 - dihydrothiazolium bromide); (3) the reaction of 2-methylbenzoxazole with tetramethylene dibromide to give 3:31-tetramethylene bis - (2 - methylbenzoxazolium bromide), which is then reacted with a -anilinoacraldehyde anil hydrochloride in acetic anhydride to give 3:31 - tetramethylene bis - [2-(o  -acetanilido - D 1:3 - butadienyl -) benzoxaolium bromide]; (4) the reaction of 2-ethylmercaptobenzthiazole and ethylene dibromide to give 3:31 - dimethylene bis - (2 - ethylmercaptobenzthiazolium bromide); and (5) the reaction of lepidine with trimethylene dibromide to give 1:11 - trimethylene bis - (4 - methylquinolinium bromide), which is then reacted with N:N1-diphenylformamidine in acetic anhydride to give 1:11-trimethylene bis-(4-b -acetanilidovinylquinolinium bromide).ALSO:Dyes of the general formula: <FORM:0804670/IV (c)/1> wherein m is 0 or 1, n is 0, 1 or 2, Y is a polymethylene or xylylene radical, A is the residue of a 5- or 6-membered ketomethylene ring and B completes a 5- or 6-membered heterocyclic nucleus, are prepared by condensing a cyclic ketomethylene compound AH2 with a quaternary salt of the formula: <FORM:0804670/IV (c)/2> wherein X is bromine or iodine, and D is -S-alkyl when n is 0, or arylamino or acet arylamino when n is 1 or 2.  The ketomethylene compound may be hydantoin, thiohydantoin, 1 - phenyl - 3 - ethyl - 2 - thiohydantoin, rhodanine, N-methyl- or N-ethyl-rhodanine, N - allyl - rhodanine barbituric acid, thiobarbituric acid, 1-phenyl-3-methyl-5-pyrazolone, 3 - ethyl - 2 - thioketo - oxazoled - 4 - one or 3 - phenyl - isoxazol - 5 - one.  B may complete a nucleus of benzthiazole, benzoxazole, naphthathiazole, benzimidazole, pyridine, quinoline,1 : 3 : 4 - thiadiazole, or thiazoline.  Examples are given of the preparation of dyes wherein Y is a dimethylene, trimethylene, tetramethylene, or pentamethylene group.  According to the Provisional Specification, A may be the residue of malonitrile, cyanacetamide, methyl cyanacetate, cyanacetic acid, acetoacetamide or ethyl acetoacetate.